(1) Field of the Invention
The invention relates to an antimicrobial and non-cytotoxic coating material and to uses of said coating material.
(2) Description of Related Art
In many fields, there is a persistent need to control the settlement, reproduction and survival of microorganisms, in particular of prokaryontae and fungi. There is a frequent desire, in particular, to limit the concentration of microorganisms on a certain area, or to keep said area completely free of microorganisms—or of a specific type or species of microorganism in certain cases. This aim is striven for in particular in the medical, medical technological and sanitary-technological fields, in the broadest sense. Antimicrobial materials and coatings, such as silver-coated threads for surgery (see S. Silver, FEMS Microbiology Reviews (2003): pp. 341-353) or anti-fouling paints containing copper, are conventionally used to this end in the field of medical and sanitary products, for example. Broad-spectrum biocides, and inorganic biocides such as silver and its ions, in particular, have proved to be especially effective in this regard. In the course of time, the material treated with the biocide releases the biocide contained within it, and reduces or completely prevents the settlement or reproduction of microorganisms on the material itself, or indeed in its surroundings.
One problem in many cases is that conventional antimicrobial materials initially release a high concentration of biocide, with the consequence that the concentration of the released biocide has a toxic effect not only on the microorganisms being combated, but unintentionally on higher cells as well. This is disruptive in the case of medical products, in particular, such as wound coverings, catheters, contact lenses and implants, because a medical product treated in this way can then delay healing and result in allergies and irritation of tissue. Corresponding disadvantages also arise when biocides are released by sanitary products such as sanitary towels, tampons and diapers, and in the production and processing of foods, especially in the case of biocide-releasing packaging and biocide-releasing components for producing or processing foods. In addition, the antimicrobial effect is rapidly depleted due to leaching from the material containing the biocidic agent.
In order to eliminate these disadvantages, WO 03/024494 proposes an antimicrobial adhesive and coating material containing metallic silver particles with a silver, sodium and potassium ion concentration of less than 5 ppm, the adhesive and coating material being a synthetically produced organic material that is generally hardened after processing. The silver particles are uniformly distributed in the adhesive and coating material. Specifically, the adhesive and coating material should be a varnish or adhesive, particularly a thermoset or thermoplastic varnish or adhesive. One disadvantage of the latter, however, is that the rate of metal ion release is difficult to control or adjust.